Sound & Remote issues prevail. No fix!
It's been a couple years now and I still have the same sound issues. It's on every streaming app including The Roku channel. My main streaming is DirectTV stream but it happens with Hulu, Discover+ ,...
Forum Discussion
If your Ultra's are actually model 4670 (Settings/System/About) then the following doesn't apply:
Ultra 4640/4800/4802/4850:
1) Disable Dolby decoding/transcoding: Settings/Audio/Digital output format = Passthrough
All Roku models:
1) Disable sound modes: During playback - Press Options (*)/Volume modes = Off or Options(*)/Sound Settings/Customize sound modes = Off
Otherwise:
1) Set stereo only output: Settings/Audio/Digital output format = Stereo (since you are connecting to/through your TV & only using its speakers, your TV's Dolby decoder (if applicable) may be causing this).
2) Ad insertions/breaks are known to cause this - nothing can be done about this (complain to Roku app/service providers).
Remote issues:
1) Make sure the Roku's are connected only to a 5Ghz SSID (separate your 2.4Ghz and 5Ghz SSIDs), and try changing the 5Ghz channel in your modem/router/gateway (e.g. to 36 or 149 - do not use a DFS channel when having remote issues); this is necessary because the remote communicates with the device using WiFi Direct, and the Roku's WiFi Direct channel "follows" the main WiFi channel.
2) Do not allow your Rokus (or other streaming devices) to connect using 2.4Ghz due to the crowding/interference/bandwidth limitations in the 2.4Ghz bands unless there is no other option (e.g too far for 5Ghz).
